Named after a Japanese scientist named Shiga who discovered it in 1897, Shigella is a type of bacteria that infects the intestinal tract. Four different groups of Shigella can affect humans, with some causing a mild illness and others a more severe one.
About 18,000 cases of Shigella infection are diagnosed each year in the United States, but many more go unreported because they involve only mild symptoms and sometimes no symptoms at all. The infection is most common during the summer months. Shigella rarely infects infants younger than 6 months old, but it is common in children 2 to 4 years old, especially those in child care.
Group B is most susceptible to Shigella infection. A study on the distribution of ABO blood groups was carried out on 85 patients with clinically and bacteriologically proven shigellosis. A significant association (P less than 0.01) of blood group B was observed with shigellosis cases in comparison to controls from whom no Shigella species or other enteropathogen could be isolated. Patients with isoagglutinin B or those who possess blood group B antigen may be at a relatively increased risk of shigellosis.
1. J Assoc Physicians India 1991 Jun;39(6):452-453 Blood group and shigellosis.Sinha AK, Bhattacharya SK, Sen D, Dutta P, Dutta D, Bhattacharya MK, Pal SC